Automatic rheostat.



10 MODEL.

w vtmeoqeo PATENTED DEC. 13, 1904. R. J. LOUIS.

AUTOMATIC RHEOSTAT.\

APPLICATION FILED MAR. 4. 1903.

2 SHEETS-BREED 1.

manic: 533 @51 5 2 Md o'auegn No. 777,116. I PATENTED DEC. 13, 1904. R.J. LOUIS.

AUTOMATIC RHEOSTAT.

APPLICATION FILED MAR. 4. 1903.

NO' MODEL. 2 SHEETS-SHEET 2.

fly: 3.

are. 777,116.

Patented December 18, 1904.

ROBERT J. Louis, OF-NEW YORK, N. Y.

AUTOMATIC RHEOSTAT.

SPECIFICATION forming part of Letters Patent No. 77 7,116,

dated December 18, 1904.

Application filed Hatch 4; 1903. Serial No. 146,082. (No model.)

To ll/b whom-it may concern:

Be it known that I, ROBERT J. LOUIS, a citizen of the United States,residing in New York, borough ofManhattan, and State of New York, haveinvented certain new and useful Improvements in Automatic Rheostats, ofwhich the following is a specification.

This invention relates to automatic rheostats to be used in connectionwith incandescent lamps for spectacular effects, as in showwindows, artpaintings, stage effects, and other places where it is desired touniformly and continuously vary the brilliancy of the incandescent lampsin circuit therewith, and has for its object to provide an automatic,means whereby resistance is uniformly and continuously, cut 1n or outof the circuit containing the lamps, thereby uniformly varying thebrilliancy of the same without the objectionable flickering attendantthe rheostats hitherto in use when one or more resistancecoils are cutin or out of the circuit; and the invention has further for its objectto provide an improved automatic rheostat the resistance-wire of whichis connected with two banks of incandescent electric lamps and toprovide means to uniformly cut resistancewire in the circuit, so as todecrease the brilliancy of one bank of incandescent lamps and cutresistance-wire out of the circuit to simultaneously increase thebrilliancy of the other bank of incandescent electric lamps, which lampsmay be arranged in show-windows, in the scenery oftheaters, and suchother places where a uniformly-varying brilliancy of incandescent lampsmounted for such purposes is desirable and necessary. The lamps may bearranged more of art paintings, in which caseone bank of incandescentlamps is arranged on the front and another bank of incandescent lamps isarranged on the rear of the painting, the variation of the intensity ofthe light varying the color effects of the pigments of the paintings.

I For this purpose the invention consists of an automatic rheostatcomprising a drum, a resistance-wire wound spirally on said drum andconnected electricallywith incandescent lamps-and particularly in theframe,

a source of electric power, pedes screw-spindle at the same velocity asthe drum, guide-rods also supported by the pedestals, aslid e-piecemovable on said guide-rods and engaging the screw-spindle,contact-fingers on said slide-piece and touching the wire on the drum,but insulated from the screwspindle, a conductor connected to thecontactiingers and to the positive terminal of a source of electricpower, conductors connecting the ends of the resistance-wire on the drumwith the positive terminals of two banks of incandescent electric lamps,a conductor connecting the negative terminals of the two banks ofincandescent lamps with the negative terminal of the, source of electricpower, and means for changing the direction of rotation of the drum andscrew-spindle, for changing the direction of reciprocation of theslide-piece provided with the contact-fingers, for changing the lengthof resistance-wire on the drum in circuit with either bank of lamps; andthe invention consists, further, of certain details of construction andcombination of parts, which'will be described more fully hereinafter,and finally pointed out in the claims.

In the accompanying drawings, Figure 1 is a plan view of my improvedautomatic rheostat, showing the same connected to two banks of electricincandescent lamps. Fig. 2 is a front elevation of Fig. i. Fig. 3 is anend view of Fig. 1 drawn on a larger scale, showing the sprockets andchain transmission. Fig. 4 is a vertical transverse cross-sectipn takenon line at a of Fig. 1, also drawn on a larger scale; and Fig. 5 is awiring diagram, showing the rheostat as connected in circuit with twobanks of electric incandescent lamps.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, A represents a bed plate or board on which isscrewed a pedestal B, provided with bearings 12 for supporting the shaftS, on which is mounted a drum D, made of any suitable insulatingmaterial or of metal and lined with an insulating layer. The drum D isprovided with grooves arranged spirally on the surface of the same, inwhich is placed a resistance-wire, preferably German silver, so as to beheld in position thereby, but not entirely submerged therein. The endsof this wire pass from the cylindrical surface of the drum to' the shaftS and are here connected to collector-rings which are insulated from theshaft. The shaft S is provided at one end with a pulley P, which isconnected by a belt with a pulley p on the shaft of an electric motorM,.and provided at the other end with a sprocket a.

The pedestal B is provided with an extension B, in which the ends of twoguide-rods 5 are suitably supported. A screw-spindle is also mounted onthe pedestal extension B and is provided at one end with a sprocket cof-the same size as the sprocket at the end of the shaft S. A chain 1/passes over the sprockets a a", so as to rotate the screw-spindle at thesame velocity as the shaft S.

On the guide-rods I) is mounted aslide-piece E, provided with anextension E, which in turn is screw-threaded at its lower end E andadapted to engage the screw-spindle W. Besides the guide-rods thepedestal extension B is also provided with a contact-rod d, which isinsulated from the pedestal extension, and

with another rod 71', which is movable and provided with lugs f f ateach end of the same. This rod 91- is loosely mounted on the pedestalextension and adapted to be reciprocated in the same and attached at oneend to a handle of a reversing-switch K. One of the guideate the movablerod w with rapidity, so as to throw the switch.

The ends of the resistance-wire, wound spirally on the drum D to thesame thread as the screw-spindle W, are connected to collectorrings ii,on which rest suitable brushes or contact-fingers '5 i. To prevent thebrushes from slipping sidewise, the collector-rings are provided ontheir outer ends with guard-rings 11* i. The brushes are mounted on thepedestal extensions, but insulated therefrom b'y insulating-plates g gand connected with the pbsitive terminals of two banks of electric in plamps are darkened and the rear top lamps candescent lamps, as shown inFig. 1.

The slide-piece E is provided with contactfingers h, which are insulatedfrom the slidepiece E by a block of insulating material E and adapted toslide on or touch the resistance-wire of the drum D. Electricallyconnected with the contact-lingers It is a contact-- maker 76', whichglides along the contact-rod d. Connected with the contact-rod (17 is aconductor leading to a binding-postj", which is connected with thepositive terminal/ of a source of electrical power. One of the brushes--i for instance-is electrically connected to a bindingpost 7'', which isconnected to the positive terminal of a bank of incandescent lamps L.The other brush, 1"", is similarly connected to a binding-post j whichis connected to the positive terminal of another bank of lamps L. Thenegative terminals of these two banks of incandescent lamps are connected to the negative terminal j of the source of electrical power. 7

\The reversing-switch K, connected to the movable rod it, may be of anysuitable construction or design, the two poles j 3' being connected witha source of electrical power j The remaining poles k 5' i1 1: aresuitably connected with the terminals m m of the motor M, so that onoperating the switch the polarity of the current to the armature of themotor is altered and the direction of rotation of the same changed.

In the construction of my improved automatic rhcostat it is essentialthat the resistance-wire of the drum D'be wound to the same thread asthe screw-spindle W and that the velocity of the drum D and of thescrew-spindle W be also the same, so that when the current of the motoris turned on and the drum and screw-spindle rotated the reciprocatingslide-piece E is moved by the screw-spindle W with a speed correspondingto the unwinding of the resistance-wire of the drum' D on thecontact-lingers it. By suitably connecting with the two banks of lampsdescribed,

and shown in the drawings, any number of other lamps many varied effectsmay be produced. i

It is well known that some substances absorb certain rays of light andreflect some rays of light, assuming a constant source of light. When,however, the source of light is varied, the amount of reflected rayswill also be varied. With these underlying principles I have found thatif a number of lamps be arranged at the front top of an oil-painting anda number of lamps arranged at the rear top of thesame the variation ofthe intensity of the lamps will change the color effects of the oilpainting remarkably when either one or the other of the lamps arevaried. When the front top lamps are brightened, the rear top lamps aresimultaneously darkened, and the effects of the paintings will be due tothe reflection of the light, and when the front top brightened theeffects of the painting will be due to the penetrating of the light-raysthrough the painting, causing by the diffusion of the same through thepigments of the paintingsentirely-different color effects than when mostof the light-rays are reflected, due to the brightness of top frontlamps. It'is clear that the uniform but complementary variation of theintensity of the lamps will produce many varied effects, such as havenot been heretofore known.

The operation of my improved rheostat is as follows: The slide-piece E,provided with the contact-fingers h, being at one end of the drum D, thepower-circuitconnecting with the terminals j j is closed, therebystarting the motor M. This motor transmits its power by pulleys P, p,and a belt 9 to the shaft S, and the drum D is rotated thereby.Simultaneously the sprocket e is rotated, and this transmits its powerby chain 43' to sprocket a which in turn rotates the screw-spindle W'.Thereupon slide-piece E, which engages the threads of the screw-spindleW, is moved along the length of the spindle, and the contact-fingers itmake contact with the wire of the drum 1) in such a manner that thespirally-wound resistance-wire glides under the contact-fingers h of theslide-piece E, and as the resist: ance-wire on one side of theslide-piece E is in series with one bank of lamps L the length of theresistance-wire is continuously and uniformly cut out of circuit withthe bank of lamps L. Resistance being cut out, the brilliancy of thelamps is continually and uniformlyincreased until when all theresistance is cut out and the slide-piece E'has reached the end of itsstroke the lamps obtain their maximum brilliancy. Somewhat before theslide-piece E reaches the end of its, stroke it is' met by the helicalsprings, connected with the'lug f on the movable rod n, and incontinuing its stroke compresses thespring s. This by its resiliencyforces the rod n in the same direction and moves the handle'of thereversing-switch K, changing thereby the polarity of the current tothemotor M. This changes the rotation of the motor, drum, andscrew-spindle, and the slide-piece Eis moved by the screw-spindle W thelength of its stroke, but now in a different direction than before. Theresistance-wire of the drum which on the first stroke was cut out is newagain out in the circuit and the lamps L con:

tinuously and uniformlydecreased in brilliancy untii when all theresistance-wire is cut in the circuit and the slide-piece E reaches theend of its stroke-that is, the position a from which it started when theoperation was begunthe lamps L are dark. Here it again engages a similarspring 8 and lug f, whereby the rod n and reversing-switch K is againactuated and the current to the motor M changed in polarity, changingthereby the direction of rotation of the motor. This changes again thedirection of rotation of the drum and screw-spindle, the stroke of theslide-piece E isaga'in repeated, and the brilliancy of the lamps Lincreased.

So far but one bank of lamps has been considered. It will, however,beseen that as the ends of the resistance-wire of the drum D areconnected with the two positive terminals of the two banks of lamps LandL, as shown in Figs. 1 and 5, and the length of this resistance-wire incircuit with each bank of lamps varied by the reciprocation of theslide-piece E the brilliancy of the two banks of lamps iscomplementary-that is, when one bank attains its maximum brilliancy theother attains its minimum brilliancy, and vice versa.

Thus an improved means is provided whereby the brilliancy ofincandescent lamps may be uniformly, continuously, and automaticallyvaried without the objectionable flickering attendant the rheostats nowin use when resistance-coils are cut in or out of circuit.

For spectacular effects in art galleries two banks of lamps L L arearranged and the lamps mounted on the top part of the frame of thepainting at the front and rear of the same and connected with the endsof the resistance-wire of the drum D, as described. Thus on thereciprocation of the slide-piece E the resistance-wire on the drum 1) issimultaneously cut into circuit with one bank of lamps and cut out ofcircuit with the other bank of'lamps and the brilliancy of thelampscorrespondingly varied, producing by their uniform and continuousvariation of brilliancy illuminating effects on the painting which bringout more clearly the artistic details of the same. For use inshow-windows the lamps on the different sides of the windowi'rame areproperly connected and by their.

uniform variation spectacular efi'ects are produced, which appeal moreto the eyes of the passersby than the uniform brilliancy hitherto inuse. Moreover, the varied illumination effects serve especially to bringout to greater advantage the desirable qualities of the commoditiesexhibited. in the illumination of scenery of theaters also varieddesirable and fascinatingefilects may be produced, which serve to givethe settings even greater magnilicence and grandeur than hithertoproduced.

My improved automatic rheostat offers many advantages over those now inuse, inasmuch as it is automatic in operation and produces at the sametime a uniform variation in the brilliancy of the lamps with which it isconnected in circuit.

" Having now described my invention, I claim as new and desire to secureby Letters Patent- 1.. An automatic rheostat, comprising a drum, aresistance-wire wound spirally on said drum, lingers in contact withsaid resistance-wire and movable along the same, means for rotating saiddrum, means for reciprocating the contact-fingers, and means at each endof said drum for changing the direction of rotation of ,the drum andreciprocation of the contact-fingers, substantially as set forth.

2. An automatic rheostat, comprising a drum, a resistance-wire woundspirally on said drum, iingersin contact with said resistance-wire andmovable along the same, an electric motor for rotating the drum, meansfor reciprocating the contact-fingers longitudinally of said drum, andmeans at each end of said drum for reversing the motor and reciprocationof the contact-fingers, substantially as set forth.

3. In combination, with a rheostat,comprising a drum wound spirally withresistancewire, a screw-spindle supported longitudinally of said drum,fingers in. contact with said resistance-wire and movable by saidscrew-spindle, of means for rotating the drum and screwspindle, andmeans at each end of said drum for reversing the direction of rotationof the drum and screw-spindle, substantially as set forth. I

4. In combination, with a rheostat, comprising a drum wound spirallywith resistancewire, a screw-spindle longitudinally of said drum,lingers in contact with the resistancewire on the drum movable by saidscrew-spindie, of 'anelectric motor for rotating the drum andscrew-spindle, a reversing-switch for said motor, and means foractuating the switch when the contactfingers havereached either I end ofthe drum, substantially as set forth.

5. An automatic rheostat, comprising a drum wound spirally withresistance-wire, fingers in contact with said resistance-wire andmovable along the same, a screw-spindle,

a slide-piece, lingers on said slide-piece and in contact with theresistance-wire on the drum, an electric motor for rotating the drum andscrew-spindle, a reversing switch, and means at eaghend of the drumengaged by the slide-piece for actuating the switch, substantially asset forth.

6. An automatic rheostat, comprising a drum, a shaft for said drum, 8.resistance-wire Wound spirally on said drum, pedestals provided withbearings for the shaft, a screwspindle supported by the pedestals, anelectric motor for rotating the drum and screw-spindle, guide-rodssupported by the pedestals, a

' reciprocating slidepiece moving on said guide-rods and screw-threadedfor engaging the screw-spindle,contact-fingers on said slidepiece movingalong the wire on the drum, but insulated from the slide-piece, amovable rod supported by the pedestals and adapted to be moved therein,a reversing-switch connected with the end of the movable rod, lugs onthe movable rod at each end of the same, springs attached to the lugs tobe engaged by the slidepiece at each end of the stroke for moving therod, actuating the switch and reversing the direction of rotation of theelectric motor, a conductor connected with the contact-fingers, and aconductor connected with one end of the wire on the drum, substantiallyas set forth.

7.. An automatic rheostat, consisting of a drum, means for impartingrotary motion tosaid drum, 9. resistance-wire wound spirally on saiddrum, a screw-spindle adjacent said drum, a slide-piece engaging saidscrew-spindle movable longitudinally of said drum, contact-fingerscarried by said slide-piece and moving along said resistance-wire, aconductor connected with the contact-fingers and with the positiveterminal of a source of electric power, conductors connecting the endsof the resistance-wire on the drum with the positive terminals of twobanks of incandescent lamps, and a conductor connecting .the mega tiveterminals of the banks of incandescent lamps with the negative terminalof the source of electric power, substantially as set forth.

8. An automatic rheostat, consisting of a drum, a resistance-wire woundspirally on said drum, means for rotating the drum, fingers placed. incontact with said resistance-wire,

means for moving the contact-fingers longitudinally over said drum, aconductor connected with the contact-lingers and to the positiveterminal of a source of electric power, conduc'tors connecting the endsof the resistancewire on the drum with the positive terminals of twobanks of incandescent lamps, one bank of lamps placed at the upper frontpart of an oil-painting and the other bank of lamps placed. at the upperrear part of an oil-painting, and a conductor connecting the negativeterminals of the banks of lamps with the negative terminal of the sourceof electric power, substantially asset forth.

in testimony that I claim the foregoing as my invention 1 have signed myname in presence of two subscribing witnessea' ROBERT J. LOUIS.vlWitnesses:

G. P. Gonrnn, HENRY J Sins.

